Gold, Platinum, Silver: Purity and Stamp Marks

Precious metals are a class of metals that, while being rare, also have certain qualities that make them desirable to people for a variety of reasons – For instance, their ability to make beautiful jewelry. Eight metals are considered precious: gold, silver, and the six metals of the platinum family (palladium, platinum, osmium, iridium, ruthenium, and rhodium). These precious metals are also known as “noble” metals because they have exceptionally high surface lusters and do not rust or corrode, enabling them to last for a very long period of time, retaining their initial shine and beauty.

Gold has been one of the most sought-after materials for jewelry and other purposes. Its luster and color make for exceptionally beautiful and distinctive pieces of jewelry that do not corrode or tarnish. Over the years, many distinctive designs have been achieved using gold as base pieces or alongside other metals and elements.

Gold's malleability (or softness) makes it the easiest metal to work with, but it can be too much of a good thing. Pure gold is much too soft to be used for most types of jewelry as it would scratch and bend easily. What is, therefore, usually done is to blend it with silver or copper to derive an alloy that is more resilient and suitable for use as jewelry. The term Karat (abbreviated “k” or “kt”) is used to describe the percentage of pure gold in the alloy, starting with 24 karats as pure gold and lower karat ratings with proportionally lower percentages of gold.

GOLD PURITY

24 Karat: 99.9% Pure
22 Karat: 91.7% Pure
18 Karat: 75% Pure
14 Karat: 58.3% Pure
12 Karat: 50% Pure
10 Karat: 41.7% Pure

Silver has been popular as jewelry for a long time like gold. It’s also versatile, lustrous, and very rare. Like gold, again, it is too soft in its pure state to be utilized as jewelry and is usually alloyed with other metals to prevent scratching and distortion. The purer the silver, it is more easily scratched, bent, or otherwise damaged.

Silver is not rated by karats like gold. Instead, jewelers use the terms “fine” and “sterling” to describe very pure silver.

SILVER PURITY

800 silver — this grade of silver contains 80 percent silver and 20 percent copper or another metal.

925 sterling silver — this rating is for silver with at least 92.5 percent silver and no more than 7.6 percent of any other metal.

950 sterling silver contains at least 95 percent silver and no more than 5 percent of another metal.

Fine silver — Fine silver contains 92.5 percent silver that is too soft to be used for most jewelry but is sometimes applied in a thin coating over sterling silver to make it appear shinier.

The six metals in the platinum family are rarer and pricier than gold, also arguably the finest of the precious metals. The metals are silver-white in color and are found worldwide. They are usually strengthened with other metals like iridium, osmium, or nickel for use in jewelry. Like silver, platinum is not measured in karats but is stamped by the manufacturer with a quality mark that has been standardized to indicate its quality and purity. Pt1000 denotes pure platinum, and Pt95 and P90 are common stamp marks on finished jewelry.

Despite being the most durable, lustrous, and scratch-resistant of all metals, its scarcity means that it is an uncommon material for use in making jewelry. Artisans prefer silver and gold as raw materials for the flexibility they allow.